Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The aggregate amount of asset impairment charges, (gains) and losses related to the divestiture of businesses and unusual items incurred during an accounting period.

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The amount by which the fair value of an investment is less than the carrying amount of that investment and the decline in fair value is deemed to be other than temporary.

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Asset Impairments and Unusual Items (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Divestitures
(Gain) loss from divestitures, asset impairments and unusual items, net	$ 1		$ 28	$ 8	$ (14)
Investment impairment		$ 52
Landfill [Member]
Divestitures
Asset impairments			$ 29
Disposed of by Sale, Not Discontinued Operations [Member]
Divestitures
(Gain) loss from divestitures, asset impairments and unusual items, net					(14)
Gain (loss) on sale of assets					$ 43